EP0239988A2 - Dreiphasiger Induktionsmotor - Google Patents

Dreiphasiger Induktionsmotor Download PDF

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Publication number
EP0239988A2
EP0239988A2 EP87104743A EP87104743A EP0239988A2 EP 0239988 A2 EP0239988 A2 EP 0239988A2 EP 87104743 A EP87104743 A EP 87104743A EP 87104743 A EP87104743 A EP 87104743A EP 0239988 A2 EP0239988 A2 EP 0239988A2
Authority
EP
European Patent Office
Prior art keywords
harmonic component
grooves
phase
induction motor
order
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP87104743A
Other languages
English (en)
French (fr)
Other versions
EP0239988A3 (en
EP0239988B1 (de
Inventor
Kiyokazu C/O Nec Corporation Okamoto
Hiroshi Nippon Elec. Ind. Co Ltd. Iijima
Tetsuo Nippon Elec. Ind. Co Ltd. Endo
Yukio Nippon Elec. Ind. Co Ltd. Miyamoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
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Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Publication of EP0239988A2 publication Critical patent/EP0239988A2/de
Publication of EP0239988A3 publication Critical patent/EP0239988A3/en
Application granted granted Critical
Publication of EP0239988B1 publication Critical patent/EP0239988B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22—Rotating parts of the magnetic circuit
    • H02K1/26—Rotor cores with slots for windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K17/00—Asynchronous induction motors; Asynchronous induction generators
    • H02K17/02—Asynchronous induction motors
    • H02K17/16—Asynchronous induction motors having rotors with internally short-circuited windings, e.g. cage rotors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
    • H02K2201/06—Magnetic cores, or permanent magnets characterised by their skew

Definitions

  • the present invention relates to a three-phase induction motor and, more particularly, to a three-phase induction motor having a relatively low capacity (e.g., a power output of 1 kW or less), which can smooth torque, and which is used as a servo motor.
  • a relatively low capacity e.g., a power output of 1 kW or less
  • An induction motor is structurally simple, inexpensive, strong, and hence has been widely used as a rough constant speed motor in many industrial fields.
  • a strong potentiality as a wide range variable speed motor e.g., servo motor, has been brought about by a new control technology, such as "vector control induction motor drive".
  • air gap magnetic flux generated in an air gap between a stator (primary) core and a rotor (secondary) core includes various harmonic components (such as the 5th, 7th, 11th, 13th, 17th,... harmonic components), thereby generating magnetic flux variations.
  • the harmonic components especially the 5th and 7th harmonic components
  • a torque ripple a phenomenon in which torque varies to become large or small.
  • a conductor groove of the rotor core is generally skewed.
  • Fig. 1 is a developed view in which the circular stator and the rotor are developed.
  • the slots 2 and the conductor grooves 4 do not completely oppose each other, and a magnetic flux passage between the stator and the rotor is always provided. Therefore, magnetic flux variations in the air gap become small, and the torque ripple caused by the stator slots is reduced.
  • the harmonic components of relatively higher orders e.g., the 11th or more
  • the 5th and 7th harmonic components which largely adversely affect cannot be removed and often generate the torque ripple.
  • a method of closing an opening of the slot leads to complex manufacturing steps and hence can be adopted only to a motor in a limited field.
  • an object of the present invention to provide a three-phase induction motor, which can be manufactured by simple manufacturing steps, which generates less torque ripple, and which has the characteristics of a servo motor.
  • nth e.g., the 7th harmonic component
  • a conductor groove of a rotor core is skewed by an electrical angle of 2 ⁇ /n (where n is an order of harmonic component to be removed).
  • the harmonic components of the orders, which largely adversely affect, of the harmonic components included in the air gap magnetic flux are removed. That is, when the conductor grooves of the rotor core are skewed by the electrical angle of 2 ⁇ /n, i.e., 2/n of an interval between magnetic poles, voltage vectors induced by the nth harmonic component in one rotor bar (secondary circuit) have opposite directions and are cancelled with each other, so that a current of the nth harmonic component no longer is supplied.
  • Fig. 2 is a schematic view for explaining an embodiment of the present invention, and showing a relationship between skew of conductor grooves of a rotor and a waveform of an air gap magnetic flux.
  • Fig. 2 shows a case wherein an influence of the 7th harmonic components included in the air gap magnetic flux are removed, and a description thereof will be made with reference to a 2-pole motor.
  • reference numeral 6 denotes a fundamental waveform of the air gap magnetic flux; and 7, the 7th harmonic component waveform thereof.
  • Reference symbol L denotes a magnetic pole interval; and W, a rotor core width.
  • the magnetic pole interval L is a half cycle width of the fundamental waveform 6, i.e., ⁇ in the case of a 2-pole motor since an electrical angle equals to a mechanical angle.
  • conductor grooves 4 of rotor core 3 are skewed by one cycle of the harmonic component, i.e., 2 ⁇ /n of the electrical angle.
  • the nth (7th) harmonic component voltages are induced at, e.g., points P1 and P2 of rotor bars (secondary circuit) 5 buried in the conductor grooves 4, and the induced voltage vectors have a direction and a magnitude represented by arrows. Therefore, the nth (7th) harmonic component current at the rotor bar 5 is cancelled and hence is no longer supplied. That is, in an induction motor having a rotor of the above arrangement, no torque ripple by the nth harmonic component is generated.
  • n 7
  • values of n may be determined by selecting the harmonic components, to be removed, having a large influence.
  • a desired one may be selected from the 5th, 7th, 11th, 13th, 17th,;.;.;. harmonic components.
  • the present invention can be applied to, e.g., a 2-, 4-, or 6-pole motor irrespective of the number of poles.
  • Another countermeasure for reducing the torque ripple is a manner of selecting the number of slots (grooves) of the stator core.
  • the present inventors have disclosed this method in European Application No. 87100093.1 (January 7th 1987).
  • the number of slots N is determined to satisfy the above relationships and to obtain a three-phase balanced winding.
  • Figs. 3(a) to 3(c) are views for explaining the countermeasure of selecting the number of slots of the stator core.
  • Figs. 3(a) to 3(c) show the case wherein an influence of the 5th harmonic component is removed and the number of slots N of the stator core becomes a minimal value so as to realize harmonic removal in a small-sized induction motor.
  • the number of poles l 2
  • the number of phases m 3
  • the number of grooves per pole and per phase q 2.5 (non-integer)
  • the stator winding pitch t 1 (a fractional pitch winding).
  • Fig. 3(a) is a developed view of the stator slots; Fig. 3(b) shows a magnetic flux distribution showing a fundamental wave and the 5th harmonic component to be removed; and Fig. 3(c) shows a stator winding showing a relationship between a pitch and positions of the slots.
  • reference numeral 8 denotes a fundamental wave; and 9, the 5th harmonic component.
  • N O a value obtained by dividing the number of slots N by a greatest common divisor of the number of slots N and a pole logarithm P.
  • N O /m integer
  • N O /2m integer
  • a single- and two-layer windings are possible.
  • a three-phase balanced winding cannot be realized by a non-integer, so that such a number of slots cannot be adopted.
  • an influence of the rth harmonic component (the 5th harmonic component in this example) is removed. Therefore, when skew of the conductor grooves of the rotor core, the number of slots N of the stator, and the winding pitch are determined according to the present invention, influences of the nth and rth harmonic components can be eliminated at the same time.
  • the harmonic component countermeasure is taken to both the rotor and the stator, if the higher (e.g., the 7th) harmonic component is removed at the rotor and the lower (e.g., the 5th) harmonic component is removed at the stator, skew can be performed at a small angle to facilitate manufacture of the rotor, resulting in a great advantage.
  • the harmonic components of the orders which largely adversely affect to generate the torque ripple can be selectively and directly removed, thereby realizing a three-phase induction motor with less torque ripple. Therefore, a small-sized driving source of a serve mechanism which requires a torque smoothness can be provided.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)
  • Induction Machinery (AREA)
EP87104743A 1986-04-01 1987-03-31 Dreiphasiger Induktionsmotor Expired - Lifetime EP0239988B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP75154/86 1986-04-01
JP61075154A JPS62233048A (ja) 1986-04-01 1986-04-01 三相誘導電動機

Publications (3)

Publication Number Publication Date
EP0239988A2 true EP0239988A2 (de) 1987-10-07
EP0239988A3 EP0239988A3 (en) 1988-07-20
EP0239988B1 EP0239988B1 (de) 1991-07-17

Family

ID=13568001

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87104743A Expired - Lifetime EP0239988B1 (de) 1986-04-01 1987-03-31 Dreiphasiger Induktionsmotor

Country Status (5)

Country Link
US (1) US4868438A (de)
EP (1) EP0239988B1 (de)
JP (1) JPS62233048A (de)
CN (1) CN1012546B (de)
DE (1) DE3771365D1 (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0240945A2 (de) * 1986-04-04 1987-10-14 Nec Corporation Induktionsmotor
EP1744164A2 (de) * 2005-07-15 2007-01-17 Brose Fahrzeugteile GmbH & Co. KG, Coburg Verstellsystem eines Kraftfahrzeugs mit Mitteln zur Bestimmung einer Geschwindigkeit aus der Welligkeit des Antriebsstromes
WO2016120533A1 (fr) * 2015-01-29 2016-08-04 Eomys Engineering Reduction des nuisances vibratoires et acoustiques d'une machine asynchrone

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03106869U (de) * 1990-02-16 1991-11-05
JP2672178B2 (ja) * 1990-05-15 1997-11-05 ファナック株式会社 同期電動機のロータ構造
US4994702A (en) * 1990-07-20 1991-02-19 Mitsubishi Kasei Corporation Motor
US5065590A (en) * 1990-09-14 1991-11-19 Williams International Corporation Refrigeration system with high speed, high frequency compressor motor
FI90604C (fi) * 1991-02-07 1994-02-25 Kone Oy Epätahtimoottori ja menetelmä epätahtimoottorin staattorin ja/tai roottorin valmistamiseksi
US6853105B2 (en) * 2000-05-25 2005-02-08 Mitsubishi Denki Kabushiki Kaisha Permanent magnet motor
JP3691345B2 (ja) * 2000-05-25 2005-09-07 三菱電機株式会社 永久磁石型電動機
FR2811155A1 (fr) * 2000-06-30 2002-01-04 Leroy Somer Machine asynchrone comportant quatre poles ou plus
US6707209B2 (en) * 2000-12-04 2004-03-16 Emerson Electric Co. Reduced cogging torque permanent magnet electric machine with rotor having offset sections
US6597078B2 (en) 2000-12-04 2003-07-22 Emerson Electric Co. Electric power steering system including a permanent magnet motor
US6759780B2 (en) * 2001-05-08 2004-07-06 Delphi Technologies, Inc. Fractional-slot winding motor
JP4595250B2 (ja) * 2001-06-08 2010-12-08 三菱電機株式会社 単相誘導電動機
JP5190131B2 (ja) * 2005-02-22 2013-04-24 三菱電機株式会社 誘導電動機
JP2006271187A (ja) * 2005-02-22 2006-10-05 Mitsubishi Electric Corp 回転電機
JP2007143323A (ja) * 2005-11-21 2007-06-07 Mitsubishi Electric Corp 交流励磁形発電機
US8944783B2 (en) * 2006-06-27 2015-02-03 Schlumberger Technology Corporation Electric progressive cavity pump
ITBO20090075A1 (it) * 2009-02-13 2010-08-14 Magneti Marelli Spa Macchina elettrica con singolo statore e due rotori tra loro indipendenti e veicolo stradale provvisto di tale macchina elettrica
US8912704B2 (en) * 2010-09-23 2014-12-16 Northern Power Systems, Inc. Sectionalized electromechanical machines having low torque ripple and low cogging torque characteristics
JP5620806B2 (ja) * 2010-12-22 2014-11-05 オークマ株式会社 電動機
JP6117740B2 (ja) * 2014-06-18 2017-04-19 ファナック株式会社 トルクリップルの低減構造を備える３相交流電動機

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH141979A (de) * 1927-12-24 1930-08-31 Siemens Ag Zweischichtige Wechselstromwicklung.
US2971106A (en) * 1957-12-05 1961-02-07 Westphalen Kurt Induction motors
DE2945673A1 (de) * 1979-11-12 1981-05-21 Karl 8000 München Jakob Wechselstrommotor mit kurzschlusslaeufer
US4371802A (en) * 1980-06-12 1983-02-01 Morrill Wayne J Half-pitch capacitor induction motor
US4409507A (en) * 1982-06-28 1983-10-11 Westinghouse Electric Corp. Dynamoelectric machines for multiples of three phases with unbalanced fractional-slot windings
SU1211835A1 (ru) * 1984-04-26 1986-02-15 Предприятие П/Я А-7075 Короткозамкнутый ротор асинхронного двигател
EP0229018A2 (de) * 1986-01-08 1987-07-15 Nec Corporation Drehstrom-Induktionsmotor

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3515919A (en) * 1968-07-26 1970-06-02 Gen Electric Stator assembly for single phase induction motor
CH566664A5 (de) * 1972-10-03 1975-09-15 Acomel Sa
US3979618A (en) * 1973-05-02 1976-09-07 Siemens Aktiengesellschaft Two layer winding for electric machines
DE2506573B1 (de) * 1975-02-17 1976-10-21 Siemens Ag Polumschaltbare drehstromwicklung
JPS5247121A (en) * 1975-10-11 1977-04-14 Mazda Motor Corp Suction device of multiple cylinder engine
GB1552656A (en) * 1976-07-26 1979-09-19 Nat Res Dev Electric motors or generators
DE3249217C2 (de) * 1981-12-04 1986-02-13 Portescap Elektrischer Schrittmotor
DE169307T1 (de) * 1984-05-18 1986-07-24 Nordson Corp., Amherst, Ohio Pumpe fuer heissschmelzklebstoffe mit durchlaesse aufweisenden zahnraedern.

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH141979A (de) * 1927-12-24 1930-08-31 Siemens Ag Zweischichtige Wechselstromwicklung.
US2971106A (en) * 1957-12-05 1961-02-07 Westphalen Kurt Induction motors
DE2945673A1 (de) * 1979-11-12 1981-05-21 Karl 8000 München Jakob Wechselstrommotor mit kurzschlusslaeufer
US4371802A (en) * 1980-06-12 1983-02-01 Morrill Wayne J Half-pitch capacitor induction motor
US4409507A (en) * 1982-06-28 1983-10-11 Westinghouse Electric Corp. Dynamoelectric machines for multiples of three phases with unbalanced fractional-slot windings
SU1211835A1 (ru) * 1984-04-26 1986-02-15 Предприятие П/Я А-7075 Короткозамкнутый ротор асинхронного двигател
EP0229018A2 (de) * 1986-01-08 1987-07-15 Nec Corporation Drehstrom-Induktionsmotor

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0240945A2 (de) * 1986-04-04 1987-10-14 Nec Corporation Induktionsmotor
EP0240945A3 (en) * 1986-04-04 1988-10-19 Nec Corporation Induction motor induction motor
EP1744164A2 (de) * 2005-07-15 2007-01-17 Brose Fahrzeugteile GmbH & Co. KG, Coburg Verstellsystem eines Kraftfahrzeugs mit Mitteln zur Bestimmung einer Geschwindigkeit aus der Welligkeit des Antriebsstromes
EP1744164A3 (de) * 2005-07-15 2008-07-02 Brose Fahrzeugteile GmbH & Co. KG, Coburg Verstellsystem eines Kraftfahrzeugs mit Mitteln zur Bestimmung einer Geschwindigkeit aus der Welligkeit des Antriebsstromes
WO2016120533A1 (fr) * 2015-01-29 2016-08-04 Eomys Engineering Reduction des nuisances vibratoires et acoustiques d'une machine asynchrone
FR3032313A1 (fr) * 2015-01-29 2016-08-05 Eomys Eng Reduction des nuisances vibratoires et accoustiques d'une machine asynchrone

Also Published As

Publication number Publication date
US4868438A (en) 1989-09-19
JPS62233048A (ja) 1987-10-13
EP0239988A3 (en) 1988-07-20
CN87102564A (zh) 1987-10-14
EP0239988B1 (de) 1991-07-17
DE3771365D1 (de) 1991-08-22
CN1012546B (zh) 1991-05-01

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